Radio Digest (Apr 1925-Jan 1926)

18 RADIO D I G E S T— Illustrated April 18, 1925 HOW TO OPERATE SET (Continued from page 15) It is desirable, for the sake of range, to operate the first tube in a condition known as "regenerative," at which point its efficiency as an amplifier is very high but, warns one that the first tube has gone into oscillation. Figure 2 shows the battery connections for the Federal 141. The binding posts are all on the rear of the receiver cabinet and no internal connections are required. After the receiver has been provided with a Pignre 2 if the means of controlling the regenerative condition is carried too far, a different condition is entered known as "oscillation" in which state the tube is useless for the purpose employed. By turning small dial 3 the efficiency of the first tube is increased more and more and regeneration is attained, and recognized by a hissing sound which becomes greater as the small dial is turned, until a click or thud Simplicity Volume, tone, selectivity, clarity, these are the standards of radio operation of last year. They are universally duplicated, taken for granted in any five tube set and no longer are the vital point of excellence. Just as automobiles passed from stair climbing tests to simplicity of control, so the radio has progressed from the gymnastics of operation to that of simplicity of control. Answering this demand, the Meco Radio Receiver has only two dials, only one dial to log, making it easier of operation for the novice, more convenient for the radio veteran. FIVE TUBES TWO DIALCONTROL Five Tubes provide the range, selectivity and clarity of tone that is to be expected from a superior set. Made in three models, cabinet and console by the manufacturers of famous Meco Tubes. Sold by dealers everywhere, supplied by recognized Radio Jobbers. Write us for the name of our dealer nearest you Metropolitan Electric Co. DES MOINES, IOWA MECO R4BI0 RECEHiES good antenna and a good ground connection, and the batteries have been connected properly, inspect the installation as follows: Inspection Insert the phone plug into the phone jack 5 at the bottom of the panel and listen in with the phones while the "Am Collapsible LOOP AERIALS "Europe with Lincoln Loop" writes Radio Expert W. W. Roberts — Manufacturer's Agent and Radio Expert — Norfolk, Va., wrote us March 17, 1925: Gentlemen: Please send me by parcel post to P. 0. Box (160, Norfolk, Va. the following: Two (2) Lincoln 4 Point Tapped Loop Aerials. Shin the above C. O. D. in view of the fact that I am not known to you. It may interest you to know that I have nfliciHl Itadio Broadcast confirmation of European Trans-Atlantic Reception durins [lie recent tests and that I used your Lincoln loop for this reception. Very truly yours, W. W. Eobertj. Lincoln 4-Point Tapped Loop $8.00 The only moderate priced Loop of this type nn the market. Fine for all types of "Superhels" — and neutrodync and tuned radio frequency sets, where an outside Aerial is impractical. For the requirements of any set whore it is desired to vary the inductance of the loop. Lincoln Center -Tapped Loop $6.50 For any set employing radio frequency amplification. Particularly adapted for "Super-nets" requiring1 a center tap. BUY A LINCOLN LOOP Sold by Rood dealers everywhere. If yours cannot supply you order direct giving your dealer's name. Lincoln Radio Corporation 224 North Wells St. CHICAGO plification Control" 3 (potentiometer) is rotated. A thud or hissing sound should be heard. All the amplifying tubes -when used in the "First R. P." stage should produce such sounds when the "Amplification Control" is rotated. Those tubes which do not produce such sounds are de ceiver, then trouble can be attributed to either of the latter two. After tuning in a station, remove the antenna wire and notice if the volume of the received signal is decreased or increased. If it is decreased, the indications are that the antenna is all right. Now repeat this operation with the PHONE JACK TO nTG.FRAtlE^S^ Figure 3 fective and should be replaced. For the "First R. F." and "Second R. F." stages choose those tubes which best conform to the above test. The 200 type tube (clear glass), for the "Detector" position only, should produce a distinct hissing sound when turned up brightly. If it does not it is defective. It should be operated just below the hissing point. Remove the antenna and ground wires from their respective binding posts 22 and 23 on the rear of the cabinet. Connect these two binding posts together with a wire and turn the "Amplification Control" all the way on to the right. Now, no matter what the position of the Secondary Wave Length Dial 1, a click should be heard at some point if the Antenna Wave Length Dial is turned through the full scale. Remove the wire from between the antenna and ground binding posts and replace the antenna and ground wires. If the receiver performs as described, and poor results are obtained with the antenna and ground connected to the re ground wire. If the removal of this wire does not produce any change in the volume, the ground connection is defective and a better one should be provided. The same is true of the antenna if its removal produced no change in volume. Antenna Compensation Having assurance that the receiver is in operating condition, we may proceed to adapt the antenna to the receiver. This operation is known as "compensating the antenna." Set Selectivity-Volume switch 4 and Amplification Control 3 as far to the right as possible. Secondary Wave Length Dial 1 between 80 and 90 and Antenna Compensator 7 at 1. Start Antenna Wave Length Dial 2 at 0 and rotate slowly toward the higher numbers until a distinct click or rushing sound is heard. Note the dial setting where this sound occurs. If no click or rushing sound is heard, set the Antenna Compensator at 2 and repeat. This process should be repeated with each of the five (Continued on page 20) Mo w to «* understand radio, assemble civcuiis,opemte sets, improve veception \*» A BIGGER, better, more complete book than has yet been brought out for the Radio set owner. Whether you built your own or bought it complete, there are pages and pages of material valuable to YOU. 28 pages on explanation of Radio, 18 pages of circuits, complete detailed constructional data on building six different sets, 14 pages on constructing parts, operating schedules of all stations, a two-color map showing their locations, how to operate some of the popular complete sets now on the market, log sheets for your dial settings. There has never been another book like it, yet it is FREE with a year's subscription to Radio Digest. Readers say it is worth the subscription price of $5.00. Have this volume of information at your elbow and receive Radio Digest every week — "First to Announce the Latest." Circulation Department Radio Digest 510 N. Dearborn Street Chicago, Illinois